Alcapa Repair

Anomalous origin of the left coronary artery arising from the pulmonary artery (ALCAPA) is a rare but serious congenital disease.

With the result of early diagnosis using echocardiography with color flow mapping and drastic improvements in surgical techniques have immensely improved the prognosis for patients with ALCAPA. ALCAPA may result from the following 2 reasons :

• abnormal septation of the conotruncus into the aorta and pulmonary artery
• persistence of the pulmonary buds together with involution of the aortic buds which eventually form the coronary arteries.

ALCAPA has been usually found to be an isolated anomaly. But, there have been cases of patients with ALCAPA associated with patent ductus arteriosus, ventricular septel defect, TOF and coarctation of the aorta. Some of the extremely rare variations of the origin of the coronary arteries from the main pulmonary artery include:

• The right coronary, often discovered as an incidental finding on autopsy
• The left anterior descending or circumflex branches
• Both the right and left coronary arteries, a circumstance not compatible with survival

Causes

Isolated congenital cardiac defects like patent ductus arteriosus, ventricular septal defect, TOF or coarctation of the aorta may be associated with ALCAPA.

Procedure

During cardioplegia, both the ascending aorta and the main pulmonary artery are cannulated and cross-clamped. This provides antegrade cardioplegia in the right coronary artery and the anomalous left coronary artery. If cardioplegia is instilled in the ascending aorta only, runoff and steal of cardioplegia into the main pulmonary artery via the anomalous left coronary artery may occur. With the advent of the technique of retrograde cardioplegia, cannulation of the pulmonary artery may be eliminated in some cases.

Before deciding on the site for incision, transverse aortotomy is used to visualize the aortic sinus. This ensures that an optimal location is chosen to place the coronary button for the aortocoronary anastomosis.

Intraoperative transesophageal echocardiography may be used to help identify and document abnormal flow in the ALCAPA and normal flow in the repaired/transposed coronary artery. Transesophageal echocardiography is also useful for postoperative monitoring of ventricular function and mitral valve regurgitation.

Risks

Surgical complications include:

• Bleeding
• Infection
• Heart Attack
• Stroke
• Need for further surgery

Recovery

Standard follow-up care is required after the surgical repair of ALCAPA.

Care for the sternotomy incision will be advised and children and infants should not be lifted by their arms for atleast 6-8 weeks. Long term follow up care will include the use of electrocardiography and echocardiography. In older children and adults, nuclear medicine perfusion scans and stress echocardiography would be recommended to understand the patient’s functional capacity after the operation.